1. Field
The present disclosure relates to a fuel cell system.
2. Description of the Related Art
For example, a solid polymer electrolyte fuel cell employs an electrolyte membrane made up of a polymer ion-exchange membrane. In a fuel cell, an electrolyte membrane/electrode structural body (MEA) in which a one-side surface of an electrolyte membrane is provided with an anode electrode and the other-side surface of the electrolyte membrane is provided with a cathode electrode is sandwiched between separators. An electrolyte membrane/electrode structural body is sandwiched between separators (bipolar plates) so as to constitute an electricity generating cell. In usual uses of fuel cells, a predetermined number of electricity generating cells are stacked to form a fuel cell stack such as a vehicular fuel cell stack that is mounted in a fuel cell electric vehicle.
In an example of the construction of a fuel cell, a fuel gas (hydrogen gas) stored in a fuel tank (hydrogen tank) is supplied to the anode electrode while external air (oxidant gas) is supplied to the cathode electrode by using a compressor or the like. An output adjusting apparatus of a fuel cell apparatus disclosed in, for example, Japanese Unexamined Patent Application Publication No. 7-14599 includes a variable-rotation speed compressor (compressing apparatus) provided on the air supply pipe to the fuel cell and a turbine (expanding apparatus) provided on an air discharge pipe. In this output adjusting apparatus, the compressor and the turbine are provided on the same shaft.